The present invention concerns a slewing bearing of the type capable of assuring the rotation of a mobile part relative to a fixed part. The fixed part can be the hull of a ship, for example, the chassis of a land vehicle such as a combat tank, or the lower part of a tower crane. The mobile part supports equipment that has to be oriented angularly, for example the turret of the tank or the upper part of the tower crane.
In these various applications, the need has arisen to know precisely the position and/or the angular speed of the mobile part relative to the fixed part. In the case of tower cranes, knowing the position of the upper part of the crane which includes a boom can prevent collisions between the booms of two cranes on the same site.
With this aim in mind, the use of encoders equipped with gears that mesh with teeth of the slewing bearing or with separate teeth is known in itself. It is also possible to use inductive proximity sensors on these teeth, or large diameter resolvers. However, these various systems either wear rapidly and lead to measurement errors due to operating clearances and to aging of the equipment, or are costly, difficult to adjust and bulky and require complex interfaces.
The aim of the present invention is to remedy the aforementioned drawbacks by proposing a slewing bearing equipped with a sensor that is compact, fitted and adjusted in the factory and requires no maintenance.
The object of the invention is to propose a slewing bearing equipped with a sensor integral with said bearing.